General data on Opto-electronic aim system (OEPS-30I)
Basic operating modes of the system OEPS-30I:
- survey, with viewing of zones with the various sizes;
- lock and automatic tracking of the target with range measurement;
- targeting with subscanning.
Structurally of OEPS-30I systems includes:
- optical location station OLS-30;
- helmet mounted target designation and indication system (HMTDIS) SURA-I;
- sensors unit;
- digitizers unit (DU) 23S/01
Optics-location station OLS-30
OLS-30 is intended for detection, automatic tracking and measurement of air target movement parameters on its thermal radiation, and also measurements of range to the target.
Functionally OLS-30 consists of:
- Survey-tracking thermal finder, intended for detection of targets on their thermal radiation and measurements of their co-ordinates in system of co-ordinates of the carrier plane;
- Laser range finder intended for measurement of range to air target preliminary found out by thermal finder, measurement of range to the surface target.
Thermal finder is passive (not radiating energy) device providing hiding reception and processing of infra-red radiation that allows to make their detection, definition of angular co-ordinates and auto tracking.
Laser range finder consists of a powerful source of monochromatic radiation which energy by narrow beam goes towards to target by means of angular target tracking system, and receiving unit catching energy reflected from the target.
Depending upon time which has passed from the moment of radiation till the moment of reception of energy reflected from the target, define distance to the purpose.
Helmet mounted target designation and indication system “SURA-I"
Helmet-mounted target designation and indication system allows to carry out pointing of "air-to-air" missiles heads and OLS scanner by turn of a pilot’s head in a target direction.
Sensors unit
Sensors unit is intended for measurement of angular velocities of the aircraft in respect to3 axes, aircraft overload nx and information output on the measured parameters to digitizers unit.
Digitizers unit
Digitizers unit 23S/01 is intended for transformation of the analogue information arriving from the sensors unit to digital code and its output to onboard computer (OC).
Block diagram of OEPS-30I

Essence of offered upgrade of OEPS-30I
OEPS-30I was developed in late 70ies - beginning of 80ies of the last century with application of technical solutions available for that period and existing components. Application of up-to-date technical means, especially photo detectors, methods and means of information exchange leads to possibility of creation of a new system both in terms of design and information exchange that will demand considerable expenses of time and money, changes of configuration of the aircraft and of onboard network.
Thus, considering the problem in the light of both above aspects, the upgrade solution concentrates on the following priorities:
- improvement of the system performance with maximum preservation of system design;
- minimum change of onboard network and signals of interaction with the onboard equipment.
Upgrade program envisages replacement of laser range finder 12P2 (12П2) by a laser range finder-highlighter 12P2L(12П2Л) and replacement of electronic "stuffing" of digitizers unit 23S/01.
Upgrade of range finder 12P2 to the level of range finder-highlighter 12P2L
The laser range finder 12P2 has number of essential problems, namely:
- material of the active element (niobium glass) of the laser is subject to degradation with time. Additionally, the energy radiated by laser is several times higher than practically required for system operation. Thus, the system turns out unstable and energetically "overloaded“.
- the cooling system of the active element of the laser, filled with a toxic and highly inflammable liquid, has many pipelines and joints, that significantly reduces its reliability.
The upgraded laser range finder-highlighter 12P2L provides following solutions:
- the active element is made of a material not subject to degradation (artificial garnet);
- the system of cooling of an active element, a rating and reflector lamp are designed in such a manner that all cooled elements are placed in a steel tight tank with volume of a cooling liquid 3 times bigger, than in laser range finder 12P2, that essentially reduces beam loading, increases time of continuous operation and raises reliability of system;
- the alternate diagram of radiation of laser signals (bandwidth is more narrow and frequency is higher) was introduced that allowed to install another channel (24Hz) for highlighting the missiles with laser homing heads (previously only 4 Hz channel was available for range finding purpose);
- combination of above steps along with installation of highly sensitive photo detector device (type FUO-119) allowed to achieve increase the detection range and accuracy of measurement.

Appearance of range finder 12P2 | Appearance of a range finder- highlighter 12P2L |
Measuring and matching unit 12П2/01M
Measuring and matching unit 12П2/01M is the upgraded version of 12П2/01 unit and includes a receiver module and a measurement control module.
The 12П2/01M unit is designed for reflected energy conversion to electric signal (echo-signals), and time delay measurement between synchronization (transmitted) pulses and corresponding echo signals, sending the measurement results and alarm reports to the central computer, as well as time delay calibrated test signals generating in diagnostic test modes.
Product is in serial production since 2011.
Technical characteristics:
- clock frequency, MHz................................................40;
- maximum range, measured, km……………............. 20;
- maximum supply current (+27V DC circuit)………...0.5;
interface code type…………….....two-level 32-bit serial

The 12П2/01 old version design

The 12П2/01M new version design
Optical-electronic aiming system interface unit with ADC&DAC conversion 23C/01M
Designed for an old 23C/01 interface unit substitution and repair. It is operating with the optical-electronic aiming systems of the Su-30MKI fighter aircrafts.
The new version of 23C/01, the 23C/01M is made with the new components and the state of the art technology. It has improved ADC and DAC characteristics and reliability.
Product is in serial production since 2009.
Technical characteristics:
- analog to digital conversion error less then 0.2%
from the reference voltage level half wave interval
measurement error, μs, less than..........................±2;
- code word length, bit..............................................32;
- serial interface lines.................................................5;
- power consumption (from the AC 110…122V), VA,
less than...................................................................15;
- continuous time of operating, hours, more than…...3.

The 23C/01 old version design

The 23C/01M new version design
Potential of further upgrade of OEPS-30I
Further upgrade of OEPS-30I can be carried out with introduction into structure of the system of an optic-television channel. Application of this technical solution could be carried out in OLS-30 without its cardinal alteration, but with more radical change of a design.
The optical system of a television channel is built-in into OLS-30 coaxially with the laser channel that allows to carry out exact aiming of a laser beam under the increased television image of the target, and the television automatic tracking will provide beam holding on the target after missile firing or air bomb drop.
Besides, installation of optic-television channel into OEPS-30I structure will provide solution for the problem of using Kh-25МТ and Kh-29Т missiles, and also KAB-500Kr bombs with television aiming systems. Thus, fighting efficiency of Su-30MKI Aircraft at attack of surface targets will essentially increase.

Summary of upgrade program benefits
№ | Technical characteristic | Improvement achieve |
1 | Detection range | For aerial targets range is increased from 4-5 km to 15-16 km For ground targets range is increased from 6-7 km to 18-20 km |
2 | The measured parameters accuracy | The measurement accuracy of target range increase (up to ±3m) and analog to digital conversion accuracy increases (ADC error less then 0.2%) |
3 | Reliability of the OEPS-30I as a system | Increasing mean time between failure by 30% |
4 | Maintenance routine time and quality | Decreasing the maintenance routine time and quality improving by using the new digital control schemes based on the PLM and microcontrollers |
5 | The OEPS-30I and its parts lifetime | Increasing the lifetime of the OEPS-30I and its parts (which have been upgraded) by 40% |